This invention relates generally to temperature measuring devices and more particularly to an improvement in a thermocouple-type heat sensing section of a device for measuring the temperature of the surface of a body.
With conventional thermometers using a thermocouple member, the measurement of the temperature of the surface of a body is conducted by bringing a part of the surface of the thermocouple member into direct contact with the surface of the body. In this case, when the body to be measured is a rotating member such as a fuser roll of an electrophotographic copying machine, the surface of the roll is liable to be injured due to the physical contact between the roll surface and the thermocouple metal surface. Additionally, the sliding contact therebetween produces heat as a result of friction thereby inhibiting precise measurement of the true temperature of the surface of the body. Furthermore, such a conventional thermometer is not applicable to the temperature measurement of electrical parts or metals through which an electrical current is caused to flow, due to the possible creation of a short-circuit which could occur because the thermocouple member is an electrically good conductor.